Why a 1 Series isn’t an Easy Fit for Wide Wheels and Tires The 1 Series has always been a BMW that cries for more grip. With a better power to weight ratio and a smaller size than the 3 Series, it’s narrow and staggered run-flat tire and wheel package doesn’t come close to taking advantage of the car’s true potential. If your 135i or 128i sees track or autocross time, or you just want it to handle better, wider tires on wheels designed specifically for the 1 Series will make a huge difference in its handling. Get the grip to take full advantage of the 1 Series’ potential and any power modifications you may have.

Sadly, there are few off-the-shelf options for wheel/tire packages, as the fitment specifications are very different from the common 3 Series. A wide, meaty tire on a wheel with 3 Series offsets will stick out of the fender. Stretched tires that are too narrow, aggressively rolled, flared fenders, or running excessive amounts of negative camber are some of the steps owners take to shoehorn wheels onto a 1 Series.

APEX developed a better alternative. Our 1 Series-specific wheels, EC-7, ARC-8, and AERO-7 have specifications that allow for the maximum amount of wheel and tire width, with little or no modification. There is no better way to properly fit a 255, 265, or even a 275 tire onto your 1 Series than with APEX, 1 Series-specific wheels.

Our 1 Series Test Car: ARC-8′s: 18×8.5 ET45 front with 18×9.5″ ET62 rearThis 135i with ARC-8′s is using our 1 Series-specific fitment with 18X8.5″ ET45 front and 18×9.5″ ET62 rear wheels. This is a very flexible setup that, depending on your car’s suspension setup, accommodates a 225-255 tire in front and a 245-275 in the rear. Our test 135i is a serious track car that uses Hoosier R6 track tires in 245/35/18 front and 255/35/18 rear sizes. In combination with coilovers and camber plates, this car is running r-compounds that are as wide as most 255 front and 275 rear street tires.

An Amazing Build and a Second Set of ARC-8′s Our test car is a phenomenal example of a very clever enthusiast modifying their car to be perfect on the street and the track. This article profiles their track fitment and tires but we wanted you to know they have a second set of ARC-8s with Yokohama S-Drives for their street setup: 18X8.5″ ET45 – 225/40/18 front and 18X9.5 ET62 – 255/30/18 rear.

The owner built many some of their own parts and even constructed tools to install them. With modifications to improve overall airflow, cooling, and a tune, this 135′s weak points have been cured and its strong points enhanced. Along with the Evolution Racewerks power mods, Ground Control suspension, StopTech BBK, Borla Exhaust, and APEX ARC-8′s, the owner built the oil cooler and some of the tools that allowed him to install a full M3 suspension. This 135i is the perfect combination of street-tuned and track-specific. The attention to detail in the build and “finished” result created quite a stir in the office. If you have a 135, this is a setup to take note of.

* -3.2 degrees of front camber can be achieved through the use of camber plates. This allows wider tires to fit in the front by tilting the wheel and suspension in at the top.

** Rolling fenders means to flatten the inner fender lip against the outer fender. Doing this creates, approximately, an additional 5mm of outer clearance although this is not true on all BMWs.

Details: Tires, Suspension, Camber Plates, Spacer, Brakes

Wheels — 18X8.5″ ET45 front, 18×9.5″ ET62 rear Like other wheel manufacturers, we originally only had a 3 Series front wheel fitment available (18×8.5″ ET38) for 1 Series owners. We quickly found this to be too much of a compromise. Directly bolted onto the 1 Series, this wheel with a 235/40/18 tire would just slightly stick out of the front fender and rub. It stuck out even worse in the rear, a half an inch more than the stock wheel. It was necessary to create a 1 Series-specific fitment if we were going to fit wheels/tires wide enough to maximize the car’s potential.

The new front wheel, with a 45mm offset pulls it in an additional 7mm, which eliminates the front fender-side rub the 3 Series wheel had with the 38mm offset. The only trade off, is that the wheel and tire is 7mm closer to the front suspension. Because of this, selecting the right aftermarket suspension that doesn’t waste space is important. With a number of suspension solutions that work, fitting much wider front tires on your 1 Series is possible. Coilovers are not necessary, with camber plates, stock struts and even springs can work, and in most cases they offer the most clearance.

In the rear we wanted to increase wheel width significantly. In 2009 we worked with BERK Technology, who were running a very competitive Red Line Time Attack 135i. Our testing with them lead us to produce a 9.5″ wide wheel with a very unique BMW offset, 62mm. This allowed them and other 1 Series owners/racers to run a 275 tire in aggressive applications, while at the same time allowing a 265/35/18 to directly fit onto a 100% stock 1 Series. The key to this offset is keeping the tire deeper in the fender. Any lower of an offset would result in pushing the tire out, and under compression a wide tire would hit the fender. Without our unique offset, tires as narrow as 245 (the stock size) can be difficult to fit onto a wheel of the same width.

A Square SetupOn BMWs, square*** setups are typically ideal for track and Autocross use. Unfortunately, due to the unusual offsets on the 1 Series, square setups require significant fender rolling or flaring with rubbing being accepted to even fit a 245/35/18 tire. Although it is possible to run the 18×8.5″ ET45 wheel front and rear, this fitment will usually limit the maximum usable tire size on the rear to no wider than the stock 245/35/18 size, and in many cases only a 235/40/18 all around.

A 9.5″ ET62 rear wheel actually fits much easier than an 8.5″ ET45. With this recommended staggered setup you gain a significant amount of rear grip that can handle the horsepower and torque of a modified 1 Series, and it fits cleaner.

The only recommended option for a square setup with 9.5″ wheels is to do what some APEX customers have already done. Install the Evolution Racewerks front widebody kit and use the 18X9.5″ ET62 rear fitment but with the widebody you can now use the 18X9.5″ ET22 in front.

*** Same wheel and tire size front and back

TiresWhether you plan to run R-Compounds or street tires, you can choose the same exact sized tires, or slightly narrower, with confidence knowing this wide setup fits with the supporting modifications and alignment specs listed above.

On our test vehicle, the front wheels use a 5mm spacer to allow the 245/35/18 Hoosier to clear the AST coilovers. Our testing shows that in most cases only a 3mm spacer is needed to clear the stock strut tube and certain aftermarket suspension. Even with a 5mm spacer, the wheel is a far more ideal offset than the 8.5″ ET38 version of the wheel. Narrower sizes such as 235 tires usually require no spacer. Again, this depends on the type of tire and the suspension used.

There are only a few tires size combinations that work properly on the 1 Series. 225/40/18 235/40/18, 245/35/18, and 255/35/18 are sizes that can work up front, but some sizes will require specific modifications to fit such as camber plates, spacers, and/or trimming of the fender liner. Almost every tire make/model is slightly different in shape, with some being significantly narrower, or wider for other tires of the same labeled size. It is recommended that you consult with us regarding tire sizes due to all the fitment variables that need to be considered.

A common mistake is purchasing tires in widths that are known to work, but not paying attention to the overall diameter or aspect ratio. A 245/35/18 is an extremely ideal tire size for the front of the 1 Series as it’s a wide tire that is very close to the overall diameter of the stock front tire size. We have seen many 1 Series owners mistakenly purchase 245/40/18 tires which are approximately 1 inch taller. This results in all sorts of issues, such as touching the inner fender liner while turning, contacting the suspension, and touching the fender.

Rear tires sizes should be limited to 255/35/18 and 265/35/18 street or extreme summer tires for the easiest, most direct fitment. 275/35/18 tires can work in the rear in both street and r-compound sizes, but there are some variables that can cause misfitment. It is recommended that you consult with us for all 275 tire fitments, and any r-compound fitments of 255 or wider in the rear.

Suspension & Camber Plates The Ground Control (GC) Coilovers paired with the GC Camber Plates are a large part of what makes this car so versatile. With coilovers that create maximum clearance and adjustable camber plates, this car has fitment-specific camber settings that can be easily adjusted at home or the track when switching between track and street setups.

The owner of this car actually runs a different set of APEX wheels with narrower tire sizes for the street. At the track, he can easily adjust his camber plates to properly fit the wider Hoosier tire, and optimize grip in the corners. Once the track day is over, adjusting the front camber back to stock to for ideal tire wear on the street is easy.

Camber Plates Adding negative camber (camber angle) with camber plates is almost always recommended to customers looking to run a wide, meaty tire in the front of a BMW. Without them, 245 tires will not fit on the front of a 1 Series. They are a must for proper fitment of wide front tires. In addition to added cornering grip, the adjustable plates allows your alignment to change to a more negative camber setting. Doing this pulls the top of the suspension in closer towards the engine bay. The entire suspension, wheel, tire, and brake assembly move in parallel to each other, so inner clearances stay the same, while the tire is pulled away from the outer fender. In the above photos you can see that even with these wide tire sizes, the wheel and tire can easily clear the fender both front and back even during hard cornering with a lot of compression. It’s key that a fitment does not rub under compression for it to work well on the track and street.

For this 135′s track fitment, -3.2 degrees of front camber is necessary to comfortably clear the fender in a high-compression turn. Street tire fitments with 245 and in some cases 255 tires usually only require -1.5 to -2 degrees camber to clear the strut.

Suspension Suspension dimensions can be particular to each brand and model. Wider or narrower strut bodies, longer or shorter springs, and progressive (conical) or linear (straight wound) springs are all considerations when choosing aftermarket suspension. These elements along with ride height all play a part in creating or eliminating clearance between the wheel and strut tube. The Ground Control coilovers on the this test car use shorter, 6″ linear springs, narrow diameter strut tubes, and a lower spring perches that sit above the tire. All of these dimensions help to create the necessary inner clearance to fit maximum width tires.

Below you can see that these coilovers have a lower spring perch that sits just above the widest part of the tire/rim, allowing for the most possible inner (strut) clearance. Ground Control did a great job with the design of their lower spring perch by actually removing material from the part of the perch that faces the tire. This material removal allows for even more clearance vs. many other coilovers on the market.

We are familiar with what suspensions do and do not work, in addition to understanding how to configure aftermarket suspensions to avoid fitment issues. Contact us if you have aftermarket suspension, or are considering it. We can recommend companies who offer kits that will work with this fitment and tires you use or will be using.

SpacersThe owner of this car used 5mm spacers in the front to add a little more strut clearance as needed with the 245 Hoosiers. Without them there would have only been 2mm of inner clearance, and that could have touched under cornering. Because the camber plates create a lot of fender side room, there is no problem using spacers to push a the wheel out from the strut with 3 or 5mm spacers.

If you are trying to fit an extra wide tire in the front of a 1 Series, small spacers are a great way to fine tune your fitment and achieve the perfect inner and outer clearance, and may be required in many situations.

NOTE: We’ve recently discovered through the feedback of 2 customers that in a very rare case (1 in 100), the ET45 wheel can touch the strut tube up front even with a conservative tire mounted. A 3-5mm spacer resolved the issue, and the cars could still fit street tires without any other mods. We are researching what what models may be affected, although the workaround is simple.

BrakesThe StopTech 355mm Big Brake Kit with 6 psiton ST60 calipers fits with ease behind both the ARC-8 and EC-7 wheels. We measured 18mm of clearance to the barrel and over 20mm to the spokes. Needless to say, clearance for an OEM front brake isn’t a concern at all. As expected the rear BMW Performance brakes have no clearance issues as they are noticeably smaller.

With so much clearance to the rim and spokes of the ARC-8′s, the Brembo 355′s and AP Racing 355′s won’t have a problem clearing this setup. Any 355mm or even 365mm kit will fit with ease.

Summarize This wide, staggered, fitment is the perfect example of a track setup done right, and it’s easy to replicate. The key is not to compromise:

Make sure you select a true, 1 Series-specific wheels.

Choose a tire size that is ideal, balancing aesthetics, performance, and clearance.

If you install aftermarket suspension, choose one the doesn’t get in the way and waste valuable tire space.

I think you should edit this as 285s fit no problem in the rear. I'd imagine 295s are possible

While we have seen this done, there are many variables and the perfect balance of modifications required for this to work on the rear of the 1-series. Not every tire will fit in that size on the 1-series, so we did not want to recommend a tire size that would may only sometimes work, depending on what brand, type, and sidewall it has. When we created this post, we understood that there will be many that will be trying to fit the fitment we suggested verbatim and install the necessary parts as we have recommended, so we wanted to suggest the fitment we have the most experience with. Thank you for letting us know that you are having success with the Dunlop Star Spec ZII's in 285/30/18.

Quote:

Originally Posted by P90Puma

Are the DINAN plates enough for a 255/35/18 on the front? (RE11's or RS3's)

They say they shift by 0.7* but not from what value for the total.

Unfortunately the Dinan Camber plates would not be enough, especially for RE11's or RS3's which are considered extreme performance summer tires that run much wider than normal street tires. We would recommend at the very least -1.5 degrees of camber, which would require adjustable camber plates such as Vorshlag, Ground Control, etc.

Unfortunately the Dinan Camber plates would not be enough, especially for RE11's or RS3's which are considered extreme performance summer tires that run much wider than normal street tires. We would recommend at the very least -1.5 degrees of camber, which would require adjustable camber plates such as Vorshlag, Ground Control, etc.

The M3 control arms add -0.75* and the Dinan plates -0.7*, that should get me to the minimum values correct?

The M3 control arms add -0.75* and the Dinan plates -0.7*, that should get me to the minimum values correct?

Is the issue just fender clearance? or Strut clearance as well?

Because the M3 control arms only pushes out the bottom of the wheels, you do not gain any additional fender clearance at the top of the wheel, so though the camber values may be at the minimum value, your actual clearance has not changed. The minimum value of -1.5~ degrees was suggested upon the camber being adjusted from the top of the wheel only, where you would gain fender clearance for the wider tire. With the M3 control arms, you may require more than -2 degrees of camber when all is said and done as the top of the wheel still needs to be cambered in more, even though the bottom of the wheel is pushed out and away from the car. Fender clearance would be the issue in this instance, not the strut clearance.

How much clearance are we talking about here? Enough that a fender roll (no pull) handles it?

There will be many variables that will comes into play, such as actual alignment settings and the particular tire that you decide to go with, so it is hard to give an exact amount of clearance. It is safe to say between ~5mm and ~10mm of clearance would be needed without the necessary camber at the top of the wheel, dependent on actual tire brand and type. A fender roll will not likely be enough for the tires you have mentioned (RE11's and RS3's) that run much wider.

Great write and great wheel option! Hopefully those trying to jam wider wheels and tires will read it all closely and especially note your camber and offset settings. It would seem that a front wheel offset of 42 or 43 would be better but I'm sure you chose 45 due to other design issues. I definitely wish I had a 62 rear offset, but then again I'm getting pretty used to slowing down or dodging bumps to minimize my 255 PSS rear rubbing..lol.

The ARC-8 wheel is flow-formed and VIA certified. It's 8.5" front (~18.2lbs) and 9.5" rear (~18.2lbs). It's the only 9.5" rear with 1 series specific offsets that allow for the use of wider rear tires such as 265 or 275 extreme summer/r-compound tires without fender rubbing. There has never been a single wheel failure to date (crack or anything else) other then 2-3 reports of minor bends that could only be detected on a balancer due to race/track abuse from off's or berms. They have not been sent to Germany for TUV certification as we have not seen the need to since VIA Certification has been enough for our customers.

Quote:

Originally Posted by Eyeman

Great write and great wheel option! Hopefully those trying to jam wider wheels and tires will read it all closely and especially note your camber and offset settings. It would seem that a front wheel offset of 42 or 43 would be better but I'm sure you chose 45 due to other design issues. I definitely wish I had a 62 rear offset, but then again I'm getting pretty used to slowing down or dodging bumps to minimize my 255 PSS rear rubbing..lol.

I'm glad you enjoyed the read!

Quote:

Originally Posted by i128

Amazing write up! Thanks! it will surely help when selecting my suspension set-up!

Now how about a little end of year group buy incentive on those sexy ARC-8's

Glad we were able to help with the information, we just wanted to raise awareness on the car's wheel fitments. There is no plans of a group buy in the near future, but that may change as the year progresses.

Quote:

Originally Posted by Kgolf31

For running a 17x8.5 set-up on a 128i, would one be concerned with the additional sidewall that you would see from a 17" versus 18"

For example, a properly sized tire would be 255/40/17 for front tires. Even with + -3* camber would you have trouble with rubbing under compression and high G loads.

The goal for an STX car (for me) would be to squeeze as much tire and wheel up front as possible.

Would there be a way to run a square set-up with a big spacer in the rear to attempt to run 255 squared and rotate tires.

Would to compromise on rear grip or try and utilize as much space as possible and go 265 or 275 rear?

While there is more sidewall by going with the 17" wheels, many people that have use the 17" wheels for racing has said that the difference is very minute and most people would not be able to tell. The sidewall should not flex much more than the 18" wheels, so the tires should clear under compression. As a matter of fact, one of the race car 135i's that use our ARC-8's run the same exact wheel and tire set up that you have in question.

With a squared setup, a spacer would not be required in the rear since the rear of the 1-series is very limiting, and the 18x8.5" ET45 is actually 4mm more aggressive than the 18x9.5" ET62 on the fender side, pushing the wheel out closer to the fender.

I don't fully understand your last question, can you please rephrase that? Are you looking to fit the max tire size in the rear?

While there is more sidewall by going with the 17" wheels, many people that have use the 17" wheels for racing has said that the difference is very minute and most people would not be able to tell. The sidewall should not flex much more than the 18" wheels, so the tires should clear under compression. As a matter of fact, one of the race car 135i's that use our ARC-8's run the same exact wheel and tire set up that you have in question.

With a squared setup, a spacer would not be required in the rear since the rear of the 1-series is very limiting, and the 18x8.5" ET45 is actually 4mm more aggressive than the 18x9.5" ET62 on the fender side, pushing the wheel out closer to the fender.

I don't fully understand your last question, can you please rephrase that? Are you looking to fit the max tire size in the rear?

Sorry, it was absolutely terrible phrasing on my end.

Would you recommend on going Squared on a 128i for the benefit of rotating or would you try and squeeze as much rubber in the rear and go staggered? Square and staggered both have their own set of problems (and gains), just didn't know if you guys experimented to find what suited the car better.

Would you recommend on going Squared on a 128i for the benefit of rotating or would you try and squeeze as much rubber in the rear and go staggered? Square and staggered both have their own set of problems (and gains), just didn't know if you guys experimented to find what suited the car better.

Since it looks like you do quite a bit of performance driving, the squared setup would be more beneficial in being able to rotate the tires, and neutralizing the car so that it does not understeer like it would in factory form. The squared setup is the preferred setup for dedicated track wheels, or for those looking to reduce understeer for their HPDE's and autocross events. For the majority of owners that do not see the race track or autocross events, the wider rear tires of a staggered setup would be more beneficial, especially for the 135i models with power upgrades.

What's the best setup width/offset for the 1M front conversion (with m3 control arms) on a 135i?

Thinking 275/35/18 RE11 square.

18x9.5 ET22 front ?
18x9.5 ET62 rear?

Do I still need camber plates?

I just ordered the 1M front kit.

As long as the hubs of the 1M and 1-series does not sit at a different position, and the front of the car would be identical to the 1M after the conversion, you should be able to fit the 18x9.5" ET22 with 275/35/18 RE-11's in the front. The 1M requires a little bit of added negative camber to fit a 275/35/18 in the front, so we would suggest that you have camber plates for this as a precaution, so that you don't have any rubbing issues if there are any slight differences between the 1M and your 1M front end conversion.

As long as the hubs of the 1M and 1-series does not sit at a different position, and the front of the car would be identical to the 1M after the conversion, you should be able to fit the 18x9.5" ET22 with 275/35/18 RE-11's in the front. The 1M requires a little bit of added negative camber to fit a 275/35/18 in the front, so we would suggest that you have camber plates for this as a precaution, so that you don't have any rubbing issues if there are any slight differences between the 1M and your 1M front end conversion.